Greedy object hash

README.md

@@ -20,6 +20,7 @@ Features:
     - test
 - Escaping of "`/`" (by "`~1`") and "`~`" (by "`~0`")
 - Allow usage of `-` for appending things to list (Add and Copy operation)
+- Smart list diffing with `object_hash` for efficient patches on collections with unique identifiers
 
 ## Getting started
 
@@ -52,6 +53,36 @@ iex> Jsonpatch.diff(source, destination)
 ]
 ```
 
+### Smart List Diffing with `object_hash`
+
+Use `object_hash` to generate efficient patches for lists of objects with unique identifiers, producing minimal operations instead of cascading replacements.
+
+```elixir
+iex> original = [
+  %{id: 1, name: "Alice"},
+  %{id: 2, name: "Bob"}
+]
+iex> updated = [
+  %{id: 99, name: "New"},
+  %{id: 1, name: "Alice"},
+  %{id: 2, name: "Bob"}
+]
+
+# Traditional pairwise diff - multiple replace operations
+# >> Jsonpatch.diff(original, updated)
+[
+  %{op: "add", path: "/2", value: %{id: 2, name: "Bob"}}
+  %{op: "replace", path: "/0", value: %{id: 99, name: "New"}},
+  %{op: "replace", path: "/1", value: %{id: 1, name: "Alice"}},
+]
+
+# With object_hash - single add operation
+iex> Jsonpatch.diff(original, updated, object_hash: fn %{id: id} -> id end)
+[
+  %{op: "add", path: "/0", value: %{id: 99, name: "New"}}
+]
+```
+
 ### Apply patches
 
 ```elixir
@@ -69,4 +100,4 @@ iex> Jsonpatch.apply_patch(patch, target)
 
 ## Important sources
 - [Official RFC 6902](https://tools.ietf.org/html/rfc6902)
-- [Inspiration: python-json-patch](https://github.com/stefankoegl/python-json-patch) 
+- [Inspiration: python-json-patch](https://github.com/stefankoegl/python-json-patch)

benchmarks/generic_benchmark.exs

@@ -0,0 +1,254 @@
+# Jsonpatch Diff Performance Benchmark
+# Run with: mix run test/benchmark.exs
+
+defmodule JsonpatchBenchmark do
+  @doc """
+  Prepare complex test cases for benchmarking
+  """
+  def prepare_test_cases() do
+    %{
+      "Complex Maps - E-commerce Order" => %{
+        doc: %{
+          "order_id" => "12345",
+          "customer" => %{
+            "name" => "John Doe",
+            "email" => "[email protected]",
+            "address" => %{
+              "street" => "123 Main St",
+              "city" => "Springfield",
+              "country" => "USA"
+            }
+          },
+          "items" => %{
+            "item1" => %{"name" => "Laptop", "price" => 999.99, "quantity" => 1},
+            "item2" => %{"name" => "Mouse", "price" => 29.99, "quantity" => 2}
+          },
+          "status" => "pending",
+          "total" => 1059.97
+        },
+        expected: %{
+          "order_id" => "12345",
+          "customer" => %{
+            "name" => "John Doe",
+            "email" => "[email protected]",
+            "address" => %{
+              "street" => "456 Oak Ave",
+              "city" => "Springfield",
+              "country" => "USA",
+              "zipcode" => "12345"
+            },
+            "phone" => "+1-555-0123"
+          },
+          "items" => %{
+            "item1" => %{"name" => "Gaming Laptop", "price" => 1299.99, "quantity" => 1},
+            "item3" => %{"name" => "Keyboard", "price" => 79.99, "quantity" => 1}
+          },
+          "status" => "confirmed",
+          "total" => 1379.98,
+          "discount" => 50.00
+        }
+      },
+      "Complex Lists - Task Management" => %{
+        doc: [
+          %{
+            "id" => 1,
+            "task" => "Write documentation",
+            "priority" => "high",
+            "completed" => false
+          },
+          %{"id" => 2, "task" => "Fix bug #123", "priority" => "medium", "completed" => true},
+          %{"id" => 3, "task" => "Review PR", "priority" => "low", "completed" => false},
+          %{"id" => 4, "task" => "Deploy to staging", "priority" => "high", "completed" => false},
+          %{"id" => 5, "task" => "Update tests", "priority" => "medium", "completed" => true}
+        ],
+        expected: [
+          %{
+            "id" => 1,
+            "task" => "Write comprehensive documentation",
+            "priority" => "high",
+            "completed" => true
+          },
+          %{
+            "id" => 6,
+            "task" => "Optimize database queries",
+            "priority" => "high",
+            "completed" => false
+          },
+          %{"id" => 3, "task" => "Review PR", "priority" => "medium", "completed" => false},
+          %{"id" => 7, "task" => "Setup monitoring", "priority" => "low", "completed" => false},
+          %{
+            "id" => 4,
+            "task" => "Deploy to production",
+            "priority" => "critical",
+            "completed" => false
+          }
+        ]
+      },
+      "Mixed Maps and Lists - Social Media Post" => %{
+        doc: %{
+          "post_id" => "abc123",
+          "content" => "Just had an amazing day!",
+          "author" => %{
+            "username" => "johndoe",
+            "followers" => 1250,
+            "verified" => false
+          },
+          "comments" => [
+            %{"user" => "alice", "text" => "Great to hear!", "likes" => 5},
+            %{"user" => "bob", "text" => "Awesome!", "likes" => 3}
+          ],
+          "tags" => ["happy", "life"],
+          "metadata" => %{
+            "created_at" => "2023-01-01T10:00:00Z",
+            "location" => "New York",
+            "device" => "mobile"
+          }
+        },
+        expected: %{
+          "post_id" => "abc123",
+          "content" => "Just had an absolutely amazing day! #blessed",
+          "author" => %{
+            "username" => "johndoe",
+            "followers" => 1275,
+            "verified" => true,
+            "display_name" => "John Doe"
+          },
+          "comments" => [
+            %{"user" => "alice", "text" => "Great to hear! So happy for you!", "likes" => 8},
+            %{"user" => "charlie", "text" => "Inspiring!", "likes" => 2},
+            %{"user" => "bob", "text" => "Awesome!", "likes" => 3, "reply_to" => "alice"}
+          ],
+          "tags" => ["happy", "life", "blessed", "inspiration"],
+          "metadata" => %{
+            "created_at" => "2023-01-01T10:00:00Z",
+            "updated_at" => "2023-01-01T10:15:00Z",
+            "location" => "New York",
+            "device" => "mobile",
+            "engagement_score" => 8.5
+          },
+          "reactions" => %{
+            "likes" => 45,
+            "shares" => 12,
+            "hearts" => 23
+          }
+        }
+      },
+      "Deep Nesting - Configuration Tree" => %{
+        doc: %{
+          "application" => %{
+            "name" => "MyApp",
+            "version" => "1.0.0",
+            "modules" => %{
+              "authentication" => %{
+                "enabled" => true,
+                "providers" => %{
+                  "oauth" => %{
+                    "google" => %{"client_id" => "123", "scopes" => ["email", "profile"]},
+                    "github" => %{"client_id" => "456", "scopes" => ["user:email"]}
+                  },
+                  "local" => %{"enabled" => true, "password_policy" => %{"min_length" => 8}}
+                }
+              },
+              "database" => %{
+                "primary" => %{
+                  "host" => "localhost",
+                  "port" => 5432,
+                  "name" => "myapp_db",
+                  "pool" => %{"size" => 10, "timeout" => 5000}
+                },
+                "replica" => %{
+                  "host" => "replica.example.com",
+                  "port" => 5432,
+                  "name" => "myapp_db"
+                }
+              }
+            }
+          }
+        },
+        expected: %{
+          "application" => %{
+            "name" => "MyApp",
+            "version" => "1.1.0",
+            "modules" => %{
+              "authentication" => %{
+                "enabled" => true,
+                "providers" => %{
+                  "oauth" => %{
+                    "google" => %{
+                      "client_id" => "123",
+                      "scopes" => ["email", "profile", "calendar"]
+                    },
+                    "github" => %{"client_id" => "789", "scopes" => ["user:email", "read:user"]},
+                    "microsoft" => %{"client_id" => "999", "scopes" => ["User.Read"]}
+                  },
+                  "local" => %{
+                    "enabled" => true,
+                    "password_policy" => %{"min_length" => 12, "require_symbols" => true}
+                  },
+                  "saml" => %{
+                    "enabled" => false,
+                    "metadata_url" => "https://sso.example.com/metadata"
+                  }
+                }
+              },
+              "database" => %{
+                "primary" => %{
+                  "host" => "db.example.com",
+                  "port" => 5432,
+                  "name" => "myapp_production",
+                  "pool" => %{"size" => 20, "timeout" => 10_000, "idle_timeout" => 30_000}
+                },
+                "cache" => %{
+                  "host" => "redis.example.com",
+                  "port" => 6379,
+                  "ttl" => 3600
+                }
+              },
+              "monitoring" => %{
+                "metrics" => %{"enabled" => true, "interval" => 60},
+                "logging" => %{"level" => "info", "format" => "json"}
+              }
+            },
+            "features" => %{
+              "feature_flags" => %{"new_ui" => true, "beta_features" => false}
+            }
+          }
+        }
+      }
+    }
+  end
+
+  @doc """
+  Run the benchmark
+  """
+  def run_benchmark() do
+    Benchee.run(
+      %{
+        # I was using it for performance comparision, now faster version is the default one
+        # "Faster JsonPatch" => fn %{doc: doc, expected: expected} ->
+        #   Jsonpatch.Faster.diff(doc, expected)
+        # end,
+        "JsonPatch" => fn %{doc: doc, expected: expected} ->
+          Jsonpatch.diff(doc, expected)
+        end
+      },
+      inputs: prepare_test_cases(),
+      warmup: 0.1,
+      time: 0.5,
+      memory_time: 0.2,
+      reduction_time: 0.2,
+      parallel: 2,
+      formatters: [
+        Benchee.Formatters.Console
+      ],
+      print: [
+        benchmarking: true,
+        configuration: false,
+        fast_warning: false
+      ]
+    )
+  end
+end
+
+# Run the benchmark
+JsonpatchBenchmark.run_benchmark()